Parents, germs can be a good thing. That is the message Dr. Mary Ruebush has in her book, “Why Dirt Is Good: 5 Ways to Make Germs Your Friends.”

While it sounds illogical with all the fear of germs being peddled and antibacterial soaps, alcohols and gels being advertised on television, Ruebush says that over-sanitizing actually robs our children’s bodies of the chance to stretch their germ-killing muscles. “Your immune response is just another body part that needs exercise to become strong,” she writes in her book.

What’s more, research shows this lack of exposure to germs may even cause increased instances of asthma, allergies and other auto-immune diseases. In a study of children who live in households with pets, Dr. Dennis Ownby, chief of allergy and immunology at the Medical College of Georgia, found fewer allergies not just to animals, but even to grass and dust mites.

Ruebush has a few suggestions to keep develop our children’s immune systems.

It’s okay for children to put things in their mouthsLet your children play. There is dirt in whatever your children picks up and puts in his mouth, but there’s no need to fear. The germs they ingest should set off dormant immune responses from your child’s system. Each time a reaction occurs, Ruebush says the immune response becomes faster and more effective. Like a learned response, your child’s immune system also learns by doing.

Avoid using anti-bacterial soaps or gelsBy using disinfectants, we are actually weakening the immune system and encouraging mutation in germs. “Germs are living creatures—they adapt to their environment just as we do.” Ruebush suggests to stick with regular soap and water, rinsing away any bacteria and germs without prompting them to adapt to a harsher chemical environment.

Vaccinate to invigorateVaccines are altered forms of germs and microbes. They do not produce the same devastating effects on the body, but still set off immune reactions that strengthen the body. Keep your child’s vaccination record updated, and while you’re at it, update your own record as well.

There’s no sense like the common senseOver the millions of years, Mother Nature has developed what Ruebush calls an “an unbelievable, miraculous immune response.” While it is tempting to make quick fixes, Ruebush suggests that we let nature take its course. “Plenty of fluid and a quiet environment that encourages rest will help the baby get over the cold on his own, without drugs.” That’s advice even us adults can use.